Abstract
The seam around the armhole tends to be easily opened from being stretched : the sewing thread might be frayed; the fabric might be broken; or the yarn might be slipped, depending on the material. Therefore, we experimented with the strength of the seam around the armhole by using the textile tensile strength tester, dealing with four kinds of materials such as cotton plain weave, cotton satin, polyester plain weave, and polyester crape, as well as with three kinds of yarn directions such as warp, weft, and bias in connection with four different lengths of the seam allowance such as 0.4, 0.6, 0.8 and 1.0 cm.
The results obtained are as follows :
1. The warp as well as the weft of satin fabric and polyester fabric are easily slipped around the armhole. As a result, the seam allowance must be wide for the strength of the seam.
2. In the case of bias, the strength of the seam is not affected by the length of the seam allowance.
3. In the case of the elastic or bias material, the elastic sewing thread should be used for the strength of the seam.
